• 펄프종이기술
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• 제42권1호
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• pp.64-73
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• 2010

This study was conducted to modify the surface properties of papers by formation of hydrophobic self-assembled monolayer(SAM) on paper surface with silanes. A base paper I(0.5% AKD) and base paper II(1.0-1.5% AKD) were reacted with silanes(PFDTES, DMDCS, MODDCS) by immersion method and vapor deposition method. Hydrophobic SAMs(contact angle value>$120^{\circ}C$) were obtained on all papers after treatment with $10^{\mu}l$ PFDTES for 15min, with $50^{\mu}l$ DMDCS for 30min, with $50^{\mu}l$ MODDCS for 300min. When applying PFDTES to paper surface, lower silane concentration and shorter reaction time were required, whereas MODDCS with long alkyl chain required the longest reaction time of 300min. The st$\ddot{o}$ckight sizing degree of silane treated papers were increased between 105sec(base paper I) and 130sec(base paper II). The wet tensile strength of PFDTES-treated base papers(I, II) increased by 10-34% after SAM formation. However, the wet tensile strength of the DMDCS-treated base paper(I) was found to decrease from 0.067kN/m to 0.038kN/m; this may due to the cellulose degrading as a result of generated hydrogen chloride when hydroxyl group of cellulose were reacted with DMDCS. No apparent changes of PPS roughness on silane-treated papers are observed. The ATR-IR spectrum showed absorption peak located at 465 and 1200cm-1 which can be assigned to the Si-O-C asymmetric stretching and Si-O-C bonds, respectively.

• 한국산학기술학회논문지
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• 제10권2호
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• pp.412-417
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• 2009

실크 생사의 세리신 정착을 보다 효과적으로 하기위해 멜라민과 포르말린의 혼합액에 각종 첨가제를 첨가했을 때 첨가제가 세리신 정착에 미치는 영향을 살펴보았다. 멜라민과 포르말린의 혼합액으로 세리신을 정착할 때 수분침투 기능이 있는 계면활성제로 전처리라고 수세하지 않은 경우 견고한 정착이 이루어졌고, 정착액에 과산화수소를 첨가한 경우 정착 효과가 크게 떨어지면서 단사 간에 접착하는 문제가 발생했고, 하이드로를 첨가하여 $60^{\circ}C$에서 정착하는 경우에는 표백과 동시에 세리신 정착이 가능함을 확인했다. 낮은 농도의 수산화나트륨을 첨가한 알칼리 조건에서 멜라민을 추가함으로써 매우 견고한 세리신 정착 결과를 얻었으나 염산과 메탄을 추가는 정착에 그다지 효과적이지 못했고, 염화마그네슘 추가는 오히려 세리신 정착 견고성을 크게 저하시켰다.

• 대한한방소아과학회지
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• 제12권1호
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• pp.183-210
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• 1998

Cheonggisan(CGS) is well known for its effect on such allergic disease as urticaria and atopic dermatitis. Gagamcheonggisan(GCGS) was formulated by subtracting several herbs from CGS and adding several herbs to CGS. Even though it is being used frequently in the clinicai medicine for the treatment of above hypersensitivity diseases, basic study to make sure the mechanism of its action is rare. In this study the author tried to know the effect of CGS and GCGS on the vascular permeability, contact dermatitis, granular secretion from mast cells and function of macrophages. The results obtained in this study are as follows : 1. Administration of CGS and GCGS decreased the vascular permeability induced by serotonin and histamine. The decrease by serotonin is more typical and dose-dependent. 2. Administration of CGS and GCGS inhibited foot-pad and ear swelling responses induced by sheep red blood cells and picryl chloride respectively, the inhibition of foot-pad swelling responses is bigger than that of ear swelling responses and both of them are not dependent on the dose3. Treatment of peritoneal mast cells with CGS and GCGS water extract decreased the histamine release triggered by compound 48／80 in a dose dependent fashion 4. Administration of CGS and GCGS increased the phagocvtic activity of peritoneal macrophages and treatment of peritoneal macrophages with CGS activated phagocytic function in a dose dependent fashion. 5. Administration of CGS and GCGS enhanced such reactive oxygen intermediates(ROIs) as superoxide and hydrogen peroxide production from peritoneal macrophages. 6. Treatment of CGS and GCGS activated peritoneal macrophages for the production of ROIs. The above results show that CGS and GCGS decreased the hypersensitivity reactions by inhibiting non-specific inflammatory mediator release and vascular permeability without affecting general immune responsiveness.

• KSBB Journal
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• 제14권6호
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• pp.702-706
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• 1999

대표적인 양식 해조류인 방사무늬 김 엽체를 대상으로 하여 산 처리에 의한 유전형질의 표현 변화를 differential display기법으로 비교하여 보았다. 방사무늬 김 엽체를 0.05% HCl을 첨가한 해수(pH 3.0)에서 5분간 처리한 후 각각 10분, 30분, 60분 그리고 4시간동안 멸균 해수에서 정치 배양시키면서, RNA를 추출하여 cDNA합성, PCR 증폭, agarose gel 전기영동 및 DNA 염기배열을 조사하였다. 그 결과 arbitrary primer OPA 1(CAGGCCCTTC)을 사용하여 differential display한 경우, 산 처리 후 30분간 멸균 해수에서 정치 배양한 엽체에서 특이적으로 RNA 합성이 일어나지 않은 유전자를 분리할 수 있었으며, 그 염기서열을 비교한바 이 유전자 fragment(605 bp)는 dethiobiotin synthetase 유전자와 93%의 높은 상동성을 가진 것으로 나타났다.

• 한국화재소방학회논문지
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• 제30권6호
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• pp.23-30
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• 2016

본 연구는 화학물질 운송 화학사고를 대상으로 각 연도별 사고현황, 사고유형, 사고원인 등의 화학사고 특성을 분석하였다. 그 결과 77건의 운송 화학사고 중 74건이 유 누출 유형에 의한 사고였으며, 사고 원인으로는 41건이 교통사고에 의한 화학사고였다. 또한, 사고다발 화학물질 조사에서는 46건의 사고가 유해화학물질에 의한 사고인 것으로 조사되었다. 화학물질 운송 화학사고의 예방 및 대응을 위해서는 화학물질 유 누출과 화학물질의 운송 교통사고에 의한 화학사고에 대한 예방책의 보완이 필요하며, 운송 화학사고가 발생되었을 경우 방재가 시스템적으로 신속히 이루어질 수 있도록 범국가적이고 체계적인 화학물질 운송안전 시스템을 구축하여 화학물질 운송에 적용하는 것이 필요하다.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.1
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• pp.111-116
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• 2006

The microstickes control effects of some fixing agents, including an inorganic PAC, an organic polyamine (PA) and polydiallydimethyl ammonium chloride (Pdadmac), and a high cationic starch (HCS), were investigated, together with their effects on wet end performances and physical properties of handsheets. Despite that the HCS and Pdadmac had lower cationic charge densities than the PA and PAC (the HCS being even lower), they gave higher zeta potentials to fibers, and lower turbidities, cationic demands and residual COD contents to the pulp liquid phases than the PA and PAC did. In all cases, the HCS showed even better effects than the Pdadmac. In addition, drainage speed was also much higher by the HCS treatments although paper formation was worsened. All the phenomena showed that the HCS can fix more dissolved and colloidal substances to cellulose fibers, indicating that the HCS functioned mainly with flocculation and even hydrogen bonding mechanisms. Data on optical properties further indicated that the HCS interacted preferentially with colloidal substances, since it fixed more 'dirty' microstickes to fibers which decreased more sheet brightness while increasing more sheet opacity (with both higher light absorption and scattering coefficients). Interestingly, the organic fixing agents did not decrease tensile, tearing, and folding strengths of paper sheets made from 100% recycled newsprint pulp, except when they were dosed in high amounts. On the contrary, the inorganic PAC had more serious negative effects on the strength properties, especially on folding endurance. The study suggested that proper use of the HCS can lead to better microstickies control effects than traditional agents and methods.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.281-281
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• 2014

The field emission properties of GaN are reported in the present study. To be a good field emitter, it requires a low work function, high aspect ratio, and strong mechanical stability. In the case of GaN, it has a quite low work function (4.1eV) and strong chemical/mechanical/thermal stabilities. However, so far, it was difficult to fabricate vertical GaN nanostructures with a high aspect ratio. In this study, we successfully achieved vertically well aligned GaN nanostructures with chemical vapor-phase etching methods [1] (Fig. 1). In this method, we chemically etched the GaN film using hydrogen chloride and ammonia gases at high temperature around $900^{\circ}C$. This process effectively forms vertical nanostructures without patterning procedure. This favorable shape of GaN nanostructures for electron emitting results in excellent field emission properties such as a low turn-on field and long term stability. In addition, we observed a uniform fluorescence image from a phosphor film attached at the anode part. The turn-on field for the GaN nanostructures is found to be about $0.8V/{\mu}m$ at current density of $20{\mu}A$/cm^2. This value is even lower than that of typical carbon nanotubes ($1V/{\mu}m$). Moreover, threshold field is $1.8V/{\mu}m$ at current density of $1mA$/cm^2. The GaN nanostructures achieved a high current density within a small applied field range. We believe that our chemically etched vertical nanostructures are the promising structures for various field emitting devices.

• 대한환경공학회지
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• 제36권2호
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• pp.103-108
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• 2014

하수슬러지의 해양투기 규제에 따른 처리대안으로 석탄화력발전소 보조연료로서의 활용이 제안되고 있다. 슬러지를 석탄과 혼합하여 사용한다면 연료의 조성변화로 인하여 산성가스의 배출특성이 달라질 것으로 예상된다. 본 연구에서는 국내 하수처리장 7곳에서 발생한 하수슬러지를 수거하여 석탄과 혼합한 뒤 실험실 규모의 연소로에서 연소시킨 후 배출되는 질소산화물($NO_x$), 이산화황($SO_2$), 염화수소(HCl), 염소($Cl_2$) 가스를 분석하였다. $NO_x$는 슬러지 혼합에 따른 배출농도 변화가 가장 작았고, $SO_2$는 슬러지를 혼합하여 연소하였을 때 석탄 연소가스와 비교하여 높은 배출농도 증가를 보였다. HCl + $Cl_2$는 슬러지의 염소함량에 따라 서로 다른 배출농도를 보였다.

• Journal of Pharmaceutical Investigation
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• 제26권3호
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• pp.221-232
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• 1996

An abrasive, calcium hydrogen phosphate dihydrate (DCPD), was synthesized in a Box-wilson experimental design by reactions between phosphoric acid and milk of lime, and calcium chloride and sodium phosphate solutions, and stabilized with TSPP and TMP. The optimum conditions for preparation of DCPD from phosphoric acid with milk of lime were such as; reaction temp.; $51.9^{\circ}C$, conc. of lime; 25.9%, conc. of phosphoric acd; 77.9%, drying temp.; $60.2^{\circ}C$ and final pH; 6.46. The physico-chemical and pharmaceutical properties of DCPD were showed as follows: glycerin absorption value(68 ml/100g), whiteness(99.5%), particle size(10.9 nm), pH(7.8), and set test(pass). XRD and SEM of DCPD indicated a monoclinic system crystallographically. $N_2$ adsorption isotherm curve by BET showed non porous type II form. The micromeritic parameters of DCPD showed that surface area was $3.27{\sim}4.6\;cm^{2}/g$ and pore volume, pore area and pore radius were negligible. The rheogram of the toothpaste containing DCPD showed pseudoplastic flow with yield value of 321, and thixotropic behavior forming hysteresis loop. These results meet the requirements as abrasive standard, and sythesized DCPD is expected as a good dental abrasive such as a high quality grade in practice.

• 한국식생활문화학회지
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• 제9권2호
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• pp.131-136
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• 1994

한국산 씀바귀(Lactuca dentata Makino)의 ethylacetate 추출물에서 6 종류의 flavonoid 성분이 TLC에 의해서 검출 되었으며, 이들은 극성에 따라서 A에서 F가지 명명되었다. 그들 중 주성분으로 생각되는 물질 E를 column chromatography을 이용하여 분리정제 하였다. 물질 E의 녹는 점은 $249.5^{\circ}C-251^{\circ}C$ 로 나타났으며, 그 구조를 밝히기 위하여, 물질 E와 이를 가수분해한 genin에 대한 여러가지 shift reagent에서 UV와 IR분석을 하고 또한 물질 E와 그의 acetyl 유도체에 대한 NMR 분석을 하였으며 물질 E에 결합된 당은 TLC에 의하여 확인하였다. 이와같은 분석 결과에서 물질 E는 luteolin 모핵에 glucose가 결합된 $luteolin-7-0-{\beta}-D-glucoside$로서 확인되었다.